Circuit breaker



Nov. 27, 1934. w F, BORGERD T AL 1,982,463

v CIRCUIT BREAKER Filed July 20, 1933 M x a H w w 40 ture or breaking of the lever Patented Nov. 27, 1934 UNITED STATES PATENT OFFICE cago, Ill., assignors to International Harvester Company, a corporation of New Jersey Application July 20, 1933, Serial No. 681,323

Claims.

This invention relates to a circuit breaker of the type used as timers for ignition apparatus. Among the objects of the invention is the provision of an ignition timer or circuit breaker 5 mechanism which possesses certain novel features and which may be produced at a relatively low cost.

A further object of the invention is to provide a contact breaker assembly which will provide supporting means for the movable breaker point, of simple construction and eflicient in operation, yet of the least practical mass whereby the circuit breaker is particularly adapted for high speed operation.

Other objects and advantages of the present invention will be apparent from the following description of the embodiment illustrated in the drawing, in which:

Figure 1 is a plan view of a timer embodying the invention;

Figure 2 is a section taken on the line 22 of Figure 1;

Figure 3 is a section taken on the line 33 of Figure 1; and,

5 Figure 4 is a section taken on the line 4-4 of Figure 1.

In the present high speed automotive type of engines it has been found necessary to provide circuit breaker mechanism which will be sufli- 0 ciently responsive to high speed operation and which will provide a long life of efliciency without material failure in operation. The circuit breaker structures of the design previously used for slower speed automotive engines function poorly or fail to operate at all when they are driven by the higher speeds demanded by present day engineering. Some of these failures are due to sluggishness in the operation of the circuit breaker lever while others are due to rupitself. To overcome these difliculties, circuit breakers have been designed having very light oscillating parts of sufficient durability to withstand continued operation at high speed.

With particular reference to the drawing, 10 indicates a circuit breaker cup formed by a drawing operation of sheet steel. A central opening 11 is formed in the bottom of the cup through which the armature shaft projects, carrying a breaker cam 12, as indicated in dotted lines in Figure 1. The cup 10 is adapted to be fitted into a housing formed on the magneto and mounted thereon for angular adjustment to provide for adjusting the timing. A section of the magneto housing 13 has been illustrated in Figure 1. A pin 14, secured to an arcuate head section 15, projects through a slot 16 formed in the housing 13. The pin 14 also projects through a slot 1'7 formed in the side wall of the timer cup 10. Screws 18 extend through slots in the head portion 15 and are threaded into the housing 13.

It will be understood that, by loosening the screws 18, the pin 14 may be adjusted circumferentially of the timer cup 10. The length of the slot 1'7 provides the maximum adjustment for advancing and retarding the spark as produced by the timer. In the construction of this device it is intended that the position of the stop pin 14 be determined during thefactory 8.5- sembly of the device, after which the screws 18 are soldered into position to prevent subsequent misadjustment. A slot 19 extending radially from the outer wall into the base portion of the cup provides a space to permit withdrawal of the cup from the housing, said slot being also con tinued up the side wall to the circumferentially positioned slot 17.

A breaker arm 20 formed from light gauge sheet metal bent over into two side portions and a face portion is provided with a bearing bushing 21 press-fitted into flanges 22 formed around aligned openings in the inner portions. Said bushing is formed of insulating material and is rotatably mounted on the breaker arm post 23, which is secured to the circuit breaker cup by a riveted head, as best shown in Figure 4. Opposite the riveted end, said post is bored out to form a chamber for receiving a lubricant and a retaining felt 24. Openings are provided in said post to deliver lubricant from said chamber and retaining said felt to the bearing surface between the outside of the post and the interior of the bushing 21.

A breaker rubbing block 25 is secured by a rivet 26 to the face portion of the breaker arm 20. The portion of said block extending outwardly toward the breaker cam 12 lies substantially on an arc, the center of which is the breaker arm pivot. By utilizing this construction, the timing is not materially altered by wearing of the contacting portion of the block. At the breaker point end, a ridge 2'7 is formed on the face of the breaker arm to provide a shoulder against which the rubbing block 25 seats. At the other side of the rubbing block 25, the terminal end of the face portion is bent up to form a stop 28 for said block. These two stops provide a recess in which the rubbing block is permanently secured rigidly in position by the single rivet 26. A breaker point 29 is secured by welding at the 110 i the spring at'that point.

arm 20.

The stationary breaker point is mounted on a support 31. Said support has an upright portion to which the point is secured and a base portion which is slidably mounted on the bottom of the cup 10 between two upwardly pressed ribs 32. To provide means for adjusting the position of the stationary breaker point, the support 32 is provided with an upstanding extension 33 provided at its end with a slotted portion 33'. Said slotted portion is formed to provide for the insertion of a screw driver or similar tool, which also may be seated in a recess 34 formed in the bottom of thecuplll foradjusting the position of the support."'A screw 35 extends through a slot formed in the base portion of the support 31 and into a threaded element 36 secured to the bottom'of' the timer cup to provide adequate securing means forthe stationary breaker point. By loosening the screw 35, the support may be'moved irieither direction by the particular means provided or by other means, to properly adjust the distance between the contact points 29 and 30.

' -A-particular*meansis provided for bringing the current into the timer and for supporting the lead in terminal wire 37 and the spring which operates the breaker arm. Said lead-in terminal wire 37is provided with a terminal 38 formed witha cylindrical extension 39. Said extension slidablyfitsintoa sleeve 40 molded into an anchoring block 41. Said block is formed of an insulating material. The base portion of the terminal 38 seats against the outside end of the block 4l which projects a substantial distance outside-thebottom of the cup 10. Said block 41 is rigidly secured in position within the cup loby two rivets 42. Y

' The block'41 is also provided with a thin slot or recess-43 to provide means for supporting and securing the rear end of the breaker arm spring 44 and the conductor 45, whichlies alongside said 'sp'ring. The spring 44 'is formed of spring steel and the cond'uctor- 45 is formed of a soft Y copper alloy; At the breaker arm end, the spring and the conductor are secured by the same rivet 26-which-secures the rubbing block 25 in position. "At the other ends said elements are secured between an upstanding portion 46 of a securing member 47 and a bent-over portion 48 of-Lsaid member. As illustrated in Figure 1, a pair: of rivets 49 are utilized for securing the two portions of 'the'member 4'7 together with thesprin'g 44 and the conductor 45 inserted therebetween. "The member 47 has a lateral apertured'flange 50 at the top through which a headed securing screw 51 extends. Said screw is threaded into a bore 52 formed in the extension 39jo'f the terminal 38. By this construction a single screw '51 secures the spring supporting member and the terminal in position.

-The' turned over portion 48 of the securing member 47 is curved away from the breaker arm spring 44 to prevent a localized bending stress on To give support to th'e'spring 44 andas a means of grounding the magnetofan additional spring element 53, secured along with thespring 44 and the conductor 45, extends around the spring in a backingposition and to make contact with pin 14 when the magneto spark is fully retarded, thus causing spark generation by the magneto to cease. 1 V

{Iheblock 4l extends alongside the position of the cam 12 and is provided with a recess 54 into which a lubricant retaining felt 55 is positioned. A pocket 56 is left between said felt and the end of the recesss, to provide a lubricant space for a hard oil of suincient consistency to remain in the pocket.

The breaker arm assembly, as above described, is operated as in conventional practice. The provision of a breaker arm of the'minimum of Weight permits the operation of the breaker at the high speeds demanded by modern engines. The simplified construction reduces the cost while not sacrificing essential qualities. The unitary constructioiiof the block 41 to provide for receiving the lead-in wire'for holding the breaker spring and conducting element, and for providing a lubricant pocket, is of a novel and improved construction. The formation of the contacting portion of the rubbing block 25 as an are centered on'the' axis of the breaker arm assures the same timing contact regardless of wear of the block. With this construction the magneto remains in perfecttiming as long as the breaker arm'gap is set to the correct value. The entire device is an advance over the prior art in reducing to a minimum the number of operating and stationary elements.

Applicants desire to claim as their invention any constructions falling within the scope of the appended claims.

What is claimed is:

1. In a circuit breaker assembly for magnetos and in combination therewith, a cup, a stationary contact point mounted therein, afbreaker arm carrying a contact point pivotally mounted in the cup and insulated therefrom, a spring securedat one end to the breaker arm, a block of insulating material mounted in the cup and rigidly secured thereto, said block having a portion extending through the cup, a member for securing." the breaker arm spring, said member having a portion extending over the top of the'insul'ating block, and means for securing saidportion to the block. Y I

2. In a circuit breaker assembly for magnetos and in combination therewith, a cup, a stationary contact point mounted therein, a breaker arm carrying a contact point pivotally mounted in the cup and insulated therefrom, aspring securedat one end mine breaker arm, a block of insulating material mounted in the cup and rigidly securedthereto, a recess formed in saidblock; to receive one end of the breaker arm spring, amen ber forsec'uring said spring, saidmember, having a portion secured to the springiend. and formed to seat in said recess and 'a portion extending over the top of said block, and means for securing said portion to theblock.

3. Ina circuit breaker assembly:for magnetos and in combination therewith, a cup,a stationary contact point mounted therein; a breaker arm carrying a contact point pivotally moulitd in the cup and insulated therefrom, aspringlfsecured at one end to the breaker arm, ajblockof insulating material mounte'din the cup and rigidly secured thereto, a recess formeduin said block to receive one 'end of the breaker arm spring, a member for securing said spring, said member having a portion secured to thespr ing end and formed to seat in said recess anda portion extending over the topof saidblock, 'a bore through said block, an opening in the spring se-j curing memberin alignment with said bore, a lead-in terminal seatedagainst the portion of e block tending thrbugh ean n wine-Y 50' gle securing means for securing said lead-in terminal and said spring securing member rigidly in position with respect to the block of insulating material.

4. In a circuit breaker assembly for magnetos and in combination therewith, a cup, a stationary contact point mounted therein, a breaker arm carrying a contact point pivotally mounted in the cup and insulated therefrom, a spring secured at one end to the breaker arm, a block of insulating material mounted in the cup and rigidly secured thereto, said block having a portion extending through the cup, a member for securing the breaker arm spring, said member having a portion secured to the spring end and formed to seat in said recess and a portion extending over the top of the block, a bore formed through said block, a lead-in terminal seated against the portion of the block outside the cup and formed with a portion extending into said bore, and a threaded element extending through the spring securing member and into the bore formed in the block and threaded into the portion of the terminal extending into the bore.

5. In a circuit breaker assembly for magnetos and in combination therewith, a cup, a stationary contact point mounted therein, a breaker arm carrying a contact point pivotally mounted in the cup and insulated therefrom, a spring secured at one end to the breaker arm, a block of insulating material mounted in the cup and rigidly secured thereto, a recess formed in said block to receive one end of the breaker arm spring, a member for securing said spring, said member having a, portion secured to the spring end and formed to seat in said recess and a portion extending over the top of said block, a lead-in terminal having a portion formed to seat against the insulating block, and a common securing means for securing said lead-in terminal and said spring securing member rigidly in position with respect to the insulating block.

WILLIAM F. BORGERD. CHARLES A. UHEREK. 

